HIIT Workout Plan: A 6-Week Plan You Can Actually Follow
Run these workouts on your iPhone, or hands-free on Apple Watch. Get PEAKVO2 This is a 6-week HIIT workout plan built to be followed, not just read: three sessions a week, starting with a gentle on-ramp and progressing to the Norwegian 4x4, the most research-backed interval protocol for raising VO2 max. Every session works with nothing but your bodyweight, and the whole plan fits in under 30 minutes per workout.
Most HIIT plans online are a random pile of exercises with no progression. This one has a clear arc: build tolerance for hard efforts in weeks 1 to 2, raise the intensity in weeks 3 to 4, and reach full-strength intervals in weeks 5 to 6. Follow it in order and you give your body the stimulus that actually moves VO2 max, without doing too much too soon.
Before You Start
- Three sessions a week, on non-consecutive days (for example Monday, Wednesday, Friday). The intensity, not the frequency, drives the result.
- Warm up and cool down every time. Five minutes easy before, three minutes easy after. Going from cold into all-out work is the fastest way to get hurt.
- Easy days stay easy. On the other days, do relaxed zone 2 cardio or rest. This is where you recover and build the aerobic base.
- Get medical clearance before all-out intervals if you are new to exercise, over 40, or have any cardiovascular risk factors.
The 6-Week HIIT Plan
Each session below is one HIIT workout. Do three a week. If a week feels too hard, repeat it before moving on; there is no prize for rushing.
| Week | Session structure | Intensity |
|---|---|---|
| 1 | 8 rounds: 30 seconds work, 90 seconds easy | Hard but controlled (about 80% max HR) |
| 2 | 10 rounds: 30 seconds work, 60 seconds easy | Hard (about 85% max HR) |
| 3 | Tabata: 8 rounds of 20 seconds all-out, 10 seconds rest | Very hard (about 90% max HR) |
| 4 | 2 blocks of Tabata (8 rounds each), 3 minutes easy between | Very hard |
| 5 | Norwegian 4x4: 4 rounds of 4 minutes hard, 3 minutes easy | Near maximal (90 to 95% max HR) |
| 6 | Norwegian 4x4, and hold the hard intervals a touch harder | Near maximal (90 to 95% max HR) |
The progression is deliberate. The long recoveries in week 1 let you hit each work interval hard without falling apart. As the weeks go on, the work gets longer or the rest gets shorter, until you reach the Norwegian 4x4, whose four-minute intervals sustain near-maximal effort long enough to drive the biggest VO2 max adaptation. Interval training in this range has repeatedly outperformed steady cardio for VO2 max in controlled trials (Milanović et al., 2015).
What to do in each work interval
Pick one hard exercise per session and stick with it, or rotate through a few. With no equipment, the best options are burpees, jump squats, mountain climbers, and high knees. On a machine, sprint on a bike, rower, or treadmill. The only rule that matters: during the work interval, go genuinely hard, and during the recovery, go genuinely easy.
Run the Plan in PEAKVO2
The hardest part of HIIT is the timing: watching a clock instead of training. PEAKVO2 has every session in this plan built in, HIIT 30/30, Tabata, and the Norwegian 4x4, and runs them for you full screen with automatic work and recovery phases, a countdown, and a haptic tap at each switch on iPhone or Apple Watch. There is a labeled Bodyweight option so you can do the whole plan with no equipment, and it tracks your VO2 max over the six weeks so you can see the plan working.
Heart Rate Targets
HIIT only works if the hard efforts are genuinely hard. The simplest check is heart rate: by the end of each work interval in weeks 3 to 6 you want to be at 85 to 95 percent of your maximum. If you do not know your zones, calculate them with the max heart rate calculator, and read heart rate zones for what each one trains. If you have no monitor, use the talk test: during work you should not be able to say more than a word or two.
What to Do After Week 6
Keep two hard sessions a week, most often the Norwegian 4x4 or short REHIT sprints, and fill the rest of your week with easy zone 2 base work. That polarized mix, mostly easy with a little very hard, is what keeps VO2 max climbing. Retest every 4 to 6 weeks with the same field test to confirm it is working.
Frequently Asked Questions
How many days a week should I do HIIT?
Two to three HIIT sessions a week is the sweet spot for most people, on non-consecutive days so you recover between them. This plan uses three. More than that adds injury and burnout risk without much extra benefit, because the gains come from intensity, not volume.
Can a beginner follow a HIIT workout plan?
Yes, if it starts gently. This plan opens with a two-week on-ramp of short work intervals and long recoveries to build tolerance before the harder weeks. Beginners should get medical clearance before all-out efforts and can repeat weeks 1 and 2 until they feel ready to progress.
How long until a HIIT plan improves my fitness?
Most people feel easier breathing and faster recovery within 2 to 3 weeks, and measurable VO2 max gains appear around 6 to 8 weeks. Untrained beginners improve fastest, often 10 to 15 percent in the first couple of months.
Do you need equipment for this HIIT plan?
No. Every session can be done with bodyweight alone (burpees, jump squats, mountain climbers, high knees) or on a bike, rower, or treadmill if you prefer. The plan is about intensity and structure, not equipment.
Should I do anything on the non-HIIT days?
Easy zone 2 cardio (a relaxed walk, jog, or ride where you can still talk) and rest. The easy days build the aerobic base that makes the hard sessions productive and are where most of your recovery happens. Do not turn them into more hard work.
Keep Reading
- Norwegian 4x4 Protocol: Proven HIIT to Raise VO2 Max
- Interval Training for Beginners: What It Is and How to Start
- Tabata Workouts: What They Are and How to Do Them Right
- 15 Best Exercises for HIIT Workouts
- How to Improve Your VO2 Max
References
- Milanović Z, Sporiš G, Weston M. Effectiveness of High-Intensity Interval Training (HIT) and Continuous Endurance Training for VO2max Improvements: A Systematic Review and Meta-Analysis of Controlled Trials. Sports Med. 2015;45(10):1469-1481. PubMed
- Helgerud J, Høydal K, Wang E, et al. Aerobic high-intensity intervals improve VO2max more than moderate training. Med Sci Sports Exerc. 2007;39(4):665-671. PubMed